Rett Syndrome
all information

Rett Syndrome

(Rett’s Disorder)

En Español (Spanish Version)


Rett syndrome is a developmental nervous system disorder primarily affecting girls. It is uncommon, but not rare, occurring in one out of every 10,000-23,000 female births.

Boys with the gene defect that causes this disorder are usually stillborn or die shortly after birth, though there have been a few cases where boys survive. Survival is more common in boys with Klinefelter syndrome or somatic mosaicism.

Rett syndrome can be classified into classic and atypical , depending on the symptoms.

Many people with Rett syndrome live into adulthood, but unfortunately most are severely handicapped. While many lack the ability to talk or walk, they usually have a full range of feelings and often communicate through their eyes. They usually require daily care from someone else throughout their lifetime.


The majority of cases of Rett syndrome are caused by nonhereditary, mutations in the Rett syndrome gene on one X chromosome. Females have two X chromosomes and males have one X and one Y chromosome. Males usually die from mutations in the Rett syndrome gene because they lack the second normal X chromosome which partially protects females.

The gene which is mutated in Rett syndrome affects methyl cytosine binding protein 2 (MECP2). When it is mutated, there is a deficiency of this important protein. The full significance of this is actively being evaluated.

Scientists have not yet discovered why the Rett syndrome gene is susceptible to mutation or what factors lead to this genetic damage. There do appear to be some “hot spots” on the gene which are more likely to develop mutations. Because Rett syndrome is usually nonhereditary, it does not commonly occur in multiple children within a family.

Risk Factors

A risk factor is something that increases your chance of getting a disease or condition. There are no known risk factors for Rett syndrome except being female. The mutation that causes the syndrome appears to be sporadic, occurring only in a single X chromosome, and as a result, the chances of having a second child with Rett syndrome is very low, less than 1%.


A girl with Rett syndrome will start developing normally. She will smile, move, and pick items up with her fingers. But by 18 months of age, the developmental process seems to stop or reverse itself. The age of onset and the severity of symptoms can vary. There are four stages. Symptoms include:

Stage I: Early Onset Stage

  • Age: 6 to 18 months
  • Duration: months

Symptoms may include:

  • Less eye contact with parents
  • Less interest in toys and play
  • Handwringing
  • Slow head growth
  • Calm, quiet baby

Stage II: Rapid Destructive Stage

  • Age: 1 to 4 years
  • Duration: weeks to months

Symptoms may include:

  • Small head
  • Mental retardation
  • Loss of muscle tone
  • Inability to purposely use hands
  • Loss of (previous) ability to talk
  • Repeatedly moving hands to mouth
  • Other hand movements, such as clapping, tapping, or random touching
  • Hand movements stop during sleep
  • Holding breath, gaps in breathing, taking rapid breaths
  • Irregular breathing stops during sleep
  • Teeth grinding
  • Laughing or screaming spells
  • Decreased social interactions
  • Irritability
  • Trouble sleeping
  • Tremors
  • Cold feet
  • Trouble crawling or walking

Stage III: Plateau Stage

  • Age: preschool through school years
  • Duration: years

Symptoms may include:

  • Difficulty controlling movement
  • Seizures
  • Less irritability and crying
  • Communication may improve

Stage IV: Late Motor Deterioration Stage

  • Age: when stage III ceases, can be anywhere from age 5 to 25
  • Duration: up to decades

Symptoms may include:

  • Decreased ability to walk
  • Muscle weakness or wasting
  • Stiffness of muscles
  • Spastic movements
  • Scoliosis (curvature of the spine)
  • Breathing trouble and seizures often decrease with age
  • Puberty usually begins at the expected age


A Woman with Scoliosis

© 2008 Nucleus Medical Art, Inc.


The doctor will ask about your child’s symptoms and medical history, and perform a physical and neurological exam. Evaluation can exclude other disorders such as autism . Genetic testing can often confirm the diagnosis.

Ninety-five percent of girls with Rett Syndrome, and 50% of those with atypical Rett Syndrome, have the MECP2 mutation. But not every individual with the MECP2 mutation will have Rett syndrome. Some females with MECP2 mutations may be normal or have only mild symptoms, but can then pass the gene to a daughter who can be more severely affected.

Although some of the motor functions of Rett syndrome, are similar to those of autism, most girls with Rett syndrome will prefer human contact to focusing on inanimate objects. Children with autism, more often boys, do not maintain person-to-person contact and, in contrast to girls with Rett syndrome, focus on things rather than people. These clinical differences may give the first clue in diagnosing Rett syndrome. Aside from genetic testing, the diagnosis is confirmed by comparing the physical and developmental findings with those typically found in Rett syndrome.

Tests may include:

  • Blood test—to check for the responsible genetic mutation (MECP2)
  • Electroencephalogram (EEG)—a test that records the electrical activity of the brain
  • Video-EEG—a test that combines EEG with a video to see if some of the child's movements are caused by seizures


There is no cure for Rett syndrome. People with this disease need to be monitored for skeletal and heart problems that may develop later in the disease.

Treatment aims to control symptoms and includes:


  • Anticonvulsants to control seizure activity
  • Stool softeners or laxatives if constipated
  • Drugs to help with breathing
  • Drugs to ease agitation

Nutrition Support

  • Small, frequent meals
  • Supplements
  • Tube-feeding, if the patient is unable to consume enough food
  • Fluids and high-fiber foods to help control constipation

Rehabilitation Therapies

  • Occupational therapy helps patients learn to perform daily activities, such as dressing and eating.
  • Physical therapy helps patients improve coordination and movement. It can sometimes prolong the ability to walk.
  • Therapists can recommend braces and splints.
  • Speech therapy aids in building communication skills.
  • Social workers help a family cope with caring for a child with Rett syndrome. Counselors help parents learn to manage behaviors.

Techniques for Limiting Problem Behaviors

Keeping a diary of the child's behaviors and activities helps determine the cause of agitation. The following may help to prevent or control behavior problems:

  • Warm baths
  • Massage
  • Soothing music
  • A quiet environment


There are no guidelines for the prevention of Rett syndrome because the cause is unknown and the mutation that causes it appears to be sporadic and unpredictable. If you have any questions about the risk of Rett syndrome in your family, you can talk to a genetic counselor.


International Rett Syndrome Association

National Institute of Child Health & Human Development

National Institute of Neurological Disorders and Stroke

Rett Syndrome Research Foundation


Sick Kids

Ontario Rett Syndrome Association


Nelson Textbook of Pediatrics . 16th ed. WB Saunders Co.; 2000.

Psychiatry . WB Saunders Co.; 1997.

We'll keep the genes on for you. Neurology . 2001 Mar 13.

Last reviewed November 2007 by Rimas Lukas, MD

Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.

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